I totally agree with James. If you use I-ttl flashs, SB-800, and SB-600 (nikon) you can get great resultes. However, if you use them a lot, you will find that they are inconsistant. Not that big of a deal so long as you pay close attention. I notice that when I'm shooting with the 800 as a master and two 600's wireless I almost always get a couple of shots that dont trigger the flash and in some cases you can see slight differences between shots, when they do fire. It's not enought to outweigh the beifits of use the SB's. Just keep it mind and you'll do find. I'm sure Canon has it's own issues though I dont know for sure as I dont shoot canon. . .